Conventionally, with a liquid crystal panel of a liquid crystal display device of a lateral electric field method, to prevent signals applied to a scanning signal line and a data signal line of a display region from becoming blunt due to parasitic capacitance, a thick organic insulating film is formed on the scanning signal line and the data signal line, and a common electrode is formed thereon. The parasitic capacitance between the scanning and data signal lines and the common electrode is thereby reduced, and bluntness of signals may be reduced.
However, when forming, as a mask, a resist pattern on a conductive film formed on the organic insulating film, and forming a wiring layer by etching the mask, the resist becomes thick along the edge line of the organic insulating film because the thick organic insulating film, and resist which is supposed to be removed at the time of development tends to remain in a connected manner. The resist remaining along the edge line becomes a mask covering a part of the conductive film at the time of etching the conductive film, and thus, the conductive film is made to remain, in a connected manner, along the edge line. Connecting wires that are adjacent to each other across the remaining conductive film are electrically connected, thereby resulting in a problem of leakage between the connecting wires.
Accordingly, Patent Document 1 discloses, on an array substrate constituting a liquid crystal panel, providing a protruding portion at an end portion, of an inter-layer insulating film with a large thickness, at a region sandwiched by adjacent mounting terminals so as to make the inclination of the end portion of the inter-layer insulating film gradual, before patterning a pixel electrode material formed on the inter-layer insulating film to form wires. The inclination of the inter-layer insulating film is thereby made gradual. As a result, the thickness of the resist formed on the protruding portion of the inter-layer insulating film is reduced, and the resist is prevented from remaining in a connected manner after development. Therefore, adjacent mounting terminals are not electrically connected, and no leakage is caused between the mounting terminals.